Examining the theory‐effectiveness hypothesis: A systematic review of systematic reviews

Abstract

Purpose Health interventions based on theory may be more effective than those that are not. This review of reviews synthesizes all published randomized controlled trial (RCT) meta‐analytic evidence from the last decade to examine whether theory‐based interventions were found to be associated with more effective adult health behaviour change interventions. Methods Systematic reviews including meta‐analyses were identified by searching Medline, CINAHL, PsycINFO, and CDSR. A narrative synthesis was used to summarize and analyse the evidence. Only reviews including RCTs of health behaviour change interventions with adults aged 18+ published from 2007 to 2017 were included. Results Of 8,659 articles, nine systematic reviews met inclusion criteria. The majority of reviews (n = 8) suggested no increased effectiveness for theory‐based compared to non‐theory‐based interventions for effectiveness of outcomes relating to health behaviour. Less than half of the RCTs included in the reviews reported the use of theory (85/183). Two reviews suggested interventions based on control theory, motivational interviewing, or self‐determination theory were associated with greater effectiveness for physical activity and/or dietary interventions and outcomes. Methodological and reporting issues limit the conclusions. Conclusions Theory‐based interventions as currently operationalized in systematic reviews were not found to be more effective than non‐theory‐based interventions. Methodological and reporting issues at study and review level may not reflect the true utility of theory use within health behaviour interventions. The promotion of theory use may benefit from using a multifaceted argument, rather than a narrow focus of increased effectiveness. What is already known on this subject? Theory use is regularly promoted by claiming that it will lead to more effective behaviour change interventions. Theory use has been frequently linked to effectiveness within systematic reviews of behaviour change interventions. The theory‐effectiveness hypothesis has not been systematically examined at the systematic review level. What does this study add? Theory use as operationalized by systematic review authors was not associated with increased effectiveness within systematic reviews examining randomized controlled trials of behaviour change interventions in adults. Interventions based on control theory, motivational interviewing, or self‐determination theory were associated with greater effectiveness for physical activity and/or dietary interventions and outcomes. Theory use should be promoted using a multifaceted argument, and assertions for increased effectiveness of theory‐based interventions should only be used in domains where specific evidence exists to support this claim.

A systematic review with meta‐analyses of text message‐delivered behaviour change interventions for weight loss and weight loss maintenance

“…This requires further investigation particularly in light of the lack of associations between delivery features and weight effects found in this review. Although theory use was not found to be associated with more effective interventions, in line with previous evidence, a better understanding of the mechanisms through which SMS work is critical to optimise SMS effectiveness, including form of delivery and SMS content features. Limited information on how SMS interventions were developed was reported.…”

The effectiveness of health professional‐delivered interventions during the first 1000 days to prevent overweight/obesity in children: A systematic review

“…Of these, three had an explicit theoretical basis: Baby Milk Trial—Social Cognitive Theory, Healthy Beginnings—Health Belief Model and Social Learning Theory, and INSIGHT—Responsive Parenting . It should be noted that although interventions may not explicitly state an underlying theory, these interventions are likely to be guided by an implicit theory underpinning the selection of BCTs …”

“…Such information could assist in the testing and scale‐up of interventions. Interventions based on theory are more likely to be effective, however, some studies have found that this is not the case due to methodological and reporting issues . Importantly also, use of theory enables us to hypothesize and test how our interventions actually work, specifying the proposed causal mechanisms and the key intervention components or “behaviour change techniques” (BCTs) .…”

The development of health behaviour change interventions for childhood cancer survivors: The need for a behavioural science approach

“…Although interventions based on theory are more likely to be effective, there are several theory-related and methodological issues that may hinder this (eg, inaccuracy of the theory itself, or not fully using the theory). 25 However, without theory we cannot hypothesise how and why behaviours could change, decide which tools or techniques may be useful in changing behaviour, or understand why an intervention has succeeded or (more often) failed in initiating and maintaining behaviour change. In practical terms,…”